The present invention relates to a filtering device for blood platelets, and more particularly to a filtering device separating blood platelets from blood and/or body fluids.
There occurs adhesion and coagulation when blood platelets are contacted with any surface other than that of blood vessels due to coagulation ability thereof, and therefore, there is a problem that tissue death occurs during an operation for human body due to obturation formed by coagulated blood platelets.
Accordingly, in order to avoid unnecessary bleeding, blood platelets are removed from human body before performing operation, and then blood platelets are transfused into human body after the operation.
As a means suitable for catching such blood platelets, National Publication of Translation of International Application No. 502174/1987 discloses a device wherein blood is poured into an ultrafilter comprising hollow fibers in order to catch blood platelets and store concentrated blood platelets.
Further, Japanese Examined Patent Publication No. 54125/1983 discloses a leukocyte filtering device, wherein fibers hvaing an average diameter of under 10 .mu.m are packed into a column so that mass of fibers is characterised as possessing a bulk density of under 0.15 g/cm.sup.3.
However, the device, which catches blood platelets by the ultrafilter, as shown in National Publication of Translation of International Application No. 502174/1987, has a disadvantage that it cannot treat enough blood since coagulation of blood platelets occurs inside of the hollow fiber.
And also, the filtering device, wherein fibers are packed into a column, as shown in Japanese Examined Patent Publication No. 54125/1983, has a disadvantage that separating effeciency is low since blood platelet absorbing ratio is low.
Further, unless a bulk density is suitably selected, filtered blood tends to contain hemolysis component, so that it is necessary to carefully separate blood platelets by preventing hemolysis from occuring.